Nanoporous materials such as nanoporous polymers, nanoporous carbons, are applied widely in subjects of chemistry, biology, environment, and energy, etc., for example, in gas separation, absorption, water purification, large-molecular filtering, sensing materials, medicine transportation, catalyst carriers, hydrogen storage, super capacitor electrodes, and so on. Thus, nanoporous materials and preparation methods thereof have been widely researched, and the field thereof is considered as one of the most promising nanotechnology fields.
A key point for preparing nanoporous materials is how to control the structure and size of nano pores. Among all the methods, one method which is capable of easily adjusting nano pore structures is named as a template method. The template method comprises: mixing a template material having nano structures with a matrix material, and removing the template material by means of chemical etching to obtain a matrix material having nanoporous structures. Among the template materials, nano silicon oxide particles are applied most widely, because the preparation of the nano silicon oxide particles is simple, the nano size is easy to control, and nano silicon oxide particles have fine homogeneity.
On the other hand, with the development of the micro electric mechanical system (MEMS) technique, the MEMS is crossed with many other subjects, which provides microchips with more and more functions. Further, these functions tend to be realized in application, such as bio-chips, micro-sensors, and so on. In such cases, chemical materials and biological materials always play a key role in the performance of chips. Certain materials, such as organic polymers, can be prepared by photolithography and etching, or soft photolithography. Non-conventional materials, such as carbon materials, however, can be prepared by chemical vapor deposition (CVD) or by carbonizing photoresists so as to obtain the micro structure. Nanoporous materials have a promising application in various sensors and micro energy systems. However, it is scarcely successfully used in micro devices. The main reason is the incompatibility between the nanoporous material and the micro processing technique, or the too complicated operations during the step of adding nanoporous materials in micro devices.